Just an FYI for whoever is interested. I purchased my Waterpik Waterflosser Ultra several weeks ago and I'm happy with it. It provides a good rinse after meals and the variety of heads covers a variety of uses. The classic head rinses the gums and between the teeth and my mouth feels good afterwards. It's easier on a dry, sensitive mouth because the variety of settings for the stream flow allow some flexibility.
My dentist says nothing replaces flossing but this is a good tool to have.
My tooth decay took a sharp turn downward after getting my Water Flosser. I floss with string, brush, then use the water flosser. It rinses out the gum pockets and keeps the biofilms from turning into plaque in the pockets. If there's a sore spot somewhere, the water flossing makes it go away in a coupla days.
I think it's well worth the time.
FYI my hygenists poo pooed water machines saying they can damage the gum tissue in between your teeth. I don't floss daily and use an electric toothbrush and have had excellent dental reports.